Over the past several decades, incidence rates of non-Hodgkin's lymphoma (NHL) have increased dramatically throughout the world among both men and women. However, few concrete risk factors for NHL have been identified. Cigarette smoking and alcohol consumption have been proposed as two factors that could potentially impact the risk of NHL. Understanding the role of these behaviors in the etiology of NHL is critical due to the population prevalence of these exposures. In 2000, 23.3 percent of adults in the US reported current cigarette smoking, and 48.4 percent of adults reported current, regular consumption of alcohol. However, epidemiologic studies that have investigated the impact of cigarette smoking and alcohol on the risk of NHL have yielded inconsistent results due to relatively small sample sizes. Several epidemiologic studies have suggested that the risk of NHL from cigarette smoking and alcohol consumption varies by disease subtype and by the type of alcohol consumed. However, individual epidemiologic studies have been limited in their ability to consider the impact of risk factors on NHL by alcohol type and disease subtype because of small sample sizes. Considering the prevalence of cigarette smoking and alcohol consumption and the uncertainty surrounding the relationship between these exposures and risk of NHL, there exists an urgent need to assess the impact of smoking and drinking on NHL using a larger sample size. The International Consortium of Investigators Working on Lymphoma Epidemiologic Studies (InterLymph) was established to facilitate the cooperation between large, epidemiologic studies of NHL, providing us with a unique opportunity to explore the relationships between smoking, alcohol, and NHL. Therefore, we propose to conduct a pooled analysis of data from several population-based case-control studies that are a part of InterLymph. Due to the recent establishment of InterLymph, the proposed pooled analysis represents the first opportunity to benefit from this international collaboration. The primary specific aim of this pooled analysis is to determine if the risk of NHL is associated with cigarette smoking and alcohol consumption, and whether this risk varies by disease subtype and type of alcohol. This InterLymph-based pooled analysis will include three population-based case-control studies with similar study design, resulting in a total of 3,592 histologically-confirmed, incident cases and 4,333 population-based controls, from six SEER sites. The increased sample size that will result from the collaboration of several large, epidemiologic studies will enable us to have sufficient statistical power to examine the strength and consistency of the associations between smoking, alcohol, and NHL.